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authorJeongjun Park <aha310510@gmail.com>2024-08-23 03:11:09 +0900
committerJakub Kicinski <kuba@kernel.org>2024-08-28 17:07:42 -0700
commit0fa5e94a1811d68fbffa0725efe6d4ca62c03d12 (patch)
tree5331c970f54958f43c867cbf0bbdba8a712420a6 /drivers/net/xen-netback
parente5899b60f52a7591cfc2a2dec3e83710975117d7 (diff)
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net/xen-netback: prevent UAF in xenvif_flush_hash()
During the list_for_each_entry_rcu iteration call of xenvif_flush_hash, kfree_rcu does not exist inside the rcu read critical section, so if kfree_rcu is called when the rcu grace period ends during the iteration, UAF occurs when accessing head->next after the entry becomes free. Therefore, to solve this, you need to change it to list_for_each_entry_safe. Signed-off-by: Jeongjun Park <aha310510@gmail.com> Link: https://patch.msgid.link/20240822181109.2577354-1-aha310510@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers/net/xen-netback')
-rw-r--r--drivers/net/xen-netback/hash.c5
1 files changed, 2 insertions, 3 deletions
diff --git a/drivers/net/xen-netback/hash.c b/drivers/net/xen-netback/hash.c
index ff96f22648ef..45ddce35f6d2 100644
--- a/drivers/net/xen-netback/hash.c
+++ b/drivers/net/xen-netback/hash.c
@@ -95,7 +95,7 @@ static u32 xenvif_new_hash(struct xenvif *vif, const u8 *data,
static void xenvif_flush_hash(struct xenvif *vif)
{
- struct xenvif_hash_cache_entry *entry;
+ struct xenvif_hash_cache_entry *entry, *n;
unsigned long flags;
if (xenvif_hash_cache_size == 0)
@@ -103,8 +103,7 @@ static void xenvif_flush_hash(struct xenvif *vif)
spin_lock_irqsave(&vif->hash.cache.lock, flags);
- list_for_each_entry_rcu(entry, &vif->hash.cache.list, link,
- lockdep_is_held(&vif->hash.cache.lock)) {
+ list_for_each_entry_safe(entry, n, &vif->hash.cache.list, link) {
list_del_rcu(&entry->link);
vif->hash.cache.count--;
kfree_rcu(entry, rcu);